Question about a Prius Boattail Implementation
 

This is something I want to do but I have a question about the current Prius design. Would this require a rework of the entire rear end? Or will a continuation of the current slope work? For reference.

http://www.toyoland.com/prius-pix/2010/2010-prius.jpg

Using the tool to overlap the template this is what I ended up with. Not sure if it's correct though. If it is, despite the looks, the Prius is not quite shaped right.

http://i59.tinypic.com/qsw21g.png

Thoughts?

It looks like you have applied the template correctly - but to do it with the higher line on the window is going to be a lot harder, than keeping the existing line. Here's what I'd do: tuft test your car and see what the actual air flow on the back looks like. If you can just extend the existing surfaces (sides as well as the top) then that makes building it much easier.

You should also consider a full belly pan before moving to a boattail, as that would help make the boattail better, and you'd benefit from it whether or not you build a boattail.

I think a better match would be if you slid the template forward until you lined up the part of the template where the template's upper slope lines up with the Prius' rear upper slope and then see how it looks going back from there. If Toyota did its homework right, there should be attached flow all of the way back to the rear spoiler, but it wouldn't hurt to tuft-test to confirm it.

The Prius has a pretty good belly pan right off the line. At least the Gen 3, not sure about previous ones. I do need to do a little cleanup for the exhaust. No idea how I'd even begin to tackle the rear suspension though. :p

http://mannphoto.com/prius/bottom/smbottomcenter.jpg


Moving the template as suggested does show a much better attachment. I suppose the only way to be sure is a tuft test. I'll have to get on that. It is a rather nice day today too.

Is it me or does it look like the front and rear are towed out? :eek:

Haha, yeah, I guess the camera the guy used sorta fish-eyed the pictures. Otherwise, I don't think this car would move very far. :P

Even though the Prius underside is smoother than that of the average car, there is still a lot of room for aerodynamic improvement since it is nowhere near as smooth as the top or sides of the car.

Coroplast is flexible, so if you use it for building your underpanelling, you can install it over some of the movable parts of the suspension and the coroplast can cover and move up and down with the suspension. I did this when covering up some of the suspension arms on the aerocivic.

I don't have a lift so I wasn't able to do this, but an idea I had was to use the vinyl sheet (or something kind of similar) that you line say dinner tables with. At 1 dollar per foot from OSH the cost is negligible, and the stuff is quite tough. I used it to block the grill. You could wrap it around the (roll?) bar, and stretch it all the way back to the bumper, and then for the suspension arms wrap all of them together.

Would this table cover vinyl sheet be stiff enough not to flap and flutter in the wind? Once a surface starts fluttering, its surface drag goes way up (think of when you hold a fluttering flag up to the wind compared with holding the same size rigid sheet to the same wind).

Did some tuft testing. Looks like Toyota knew what they were doing after all. Seems to have kept good attachment and it was smooth. So when I do the boattail, it'll be a continuation of the current slope. Prius comes with good attach points too, that blade on the back has 5 bolts that hold it. Remove it, and there are 5 mount points on top ^^. Going to remove a tail light later on and see how many mount points I'll have there. See if I can get away without any extra holes.

Pretty Bold to go with a full boat tail on a 2010 ;) Kudos!

After Basjoos suggestion of moving the template forward and NeilBlanchard's suggestion to do some tuft testing to make sure the current shape was aerodynamic to continue the current shape, I believe this is more what I'll end up with.

http://i62.tinypic.com/24v7l1g.jpg

Shouldn't be too hard right? ...

A tow hitch would provide a weight bearing attachment point plus some towing ability.

I have a somewhat aerodynamic tow hitch mounted on the Beetle , it is the round tube design type ,much like the one in the photo

Attachment 15023

That's a thought! I'm going to be looking under the bumper for attach points as well. The bigger things though require more time than I usually have :( . I have to use this vehicle for work. On that note...I'm really not sure how my employer would feel about me using a aero-modded vehicle as a delivery vehicle...

...eh...what are they going to do...fire me? Pfffft...just give me more time to work on it.

Easier to ask for forgiveness than permission :)

I think so, but to be safe you could go for a thicker one than I used on my front grille. Another possibility is to attach coroplast to the areas that aren't secured to the car; the coroplast would provide rigidity while the vinyl sheet gives you an easy mounting option.

http://i62.tinypic.com/24v7l1g.jpg

Given a vehicle length about 14 1/2ft; you're showing an overall length about 21 1/2ft. I think that's longer than a parking space. (20ft?)

Also the Template assumes a half-circular cross section. If you look at it in plan, the length may be different. I got a similar result for my car and started looking for ways to truncate it.
http://ecomodder.com/forum/member-fr...ed-stinger.png

The one on the left would use a Coanda nozzle to virtually shorten the length.

*nod* Yes, I'd be working up from the bottom as well. I want to end up with something more along these lines when I'm done. Otherwise, like you said, I'd have some length issues.

http://ecomodder.com/wiki/images/thu...800px-Xl01.jpg

The other thing I really like in this picture is the rear view camera on the side. That would be my preferred setup if I can get away with it.

So your goal is perfection? :)

I saw a concept car where the rear view screens were sunk into recesses in the doors so there wouldn't be any glare on them.

Perfection....great....now all I can think about is going with a borg theme.

That is pretty cool. It's too bad most of these concept cars don't come out as is. They look so great and then they change them to what they think will sell.

I want my thorium powered car now kthnx

plan-taper
 

Here's a plan-taper template which might help.I think your boat-tailing begins around half way across the rear wheels.
http://i1271.photobucket.com/albums/...ad2/Bottom.jpg
Also,here's the Gen-II Insight.Honda has relaxed the roofline,lofting it to the Template.The Prius V also has the lofted roofline.The V's Cd is higher,but it's roof is shorter.
http://i1271.photobucket.com/albums/...ead2/04-01.jpg